The primary objective of this research project is to assess the effects on walking distance of SR 33589B administered orally for one month to patients with left ventricular dysfunction and in NYHA class I-II. Secondary objectives are to assess the effects of SR 33589B on ejection fraction, NYHA status, cardiothoracic ratio, liver and renal function. Holter parameters with respect to PVC counts, arrhythmic events, heart rate and QT variability will be measured as well as the relationship between plasma concentration of SR 33589B and its metabolite and changes in hemodynamic and electrophysiological parameters. Because of the potency of SR 33589B as compared to amiodarone (proven to be 3 to 10 times more potent in several animal models) and the fact that it appears to be less toxic, SR 33589B may provide a more effective, yet less toxic, treatment for patients with left ventricular dysfunction.